I'm the same way about foam! I'm a little worried how my board will turn out.
I've got an advantage because I'm doing finish work on a house right now.
With the right tools this can be done easily. The whole process is fairly simple and straight forward. You need at least 2 types of wood (light and dark) I cut a 9" section out of my black walnut. Square up all of the ends. Then I started cutting, with the grain, 1/4" strips. I cut out 5 of them and cut them in half.
I cut a 5" section of oak. I set my miter saw to 4* and cut off making sure to cut the triangles uniform. I was winging it a little here so there might be a better way of doing this.
Once I had my pieces cut I used wood glue and slathered them all up in this fashion.
It took a couple of days to where I felt I could do any sanding on it. I free hand cut a circle out of my dark wood and cut in half (mistake) I should have made 2 circles.
Anyway I didn't want to wait for the circle to harden for 2 days so I used some 5 minute epoxy to attach the half circle.
Luckily I was able to get 2 fins out of the 2 slabs that I had made.
Once I had them outlined it was just cutting them out on the band saw and a lot of sanding on our disc sander.